Facile 3D nanostructured ZnO-graphene hybrids for gas sensing applications

In this paper, ZnO-1.4 wt% Graphene (ZnO-G) hybrids were synthesized by sonochemistry of high acoustic power density. XRD, SEM and RAMAN spectroscopy have shown that (i) ZnO-G crystallite particles of 18 nm were obtained after drying and this was mainly due to sonoprocessing, (ii) Nanoflower-like 3D architectures of ZnO-G hybrids were obtained at pH=14, which de-structured gradually at pH of 11.5, ending with an agglomeration of nanopetals at pH=8.5, (iii) Sonochemistry created a major disorder of graphene, with G peak splitting into two peaks at 1575 cm
^-1
and 1605 cm
^-1
and (iv) maximum operation of gas sensors based on ZnO-G should be much below 450°C in air, to preserve chemical stability of ZnO-G layer.